Acute angle-closure glaucoma: Difference between revisions
| Line 32: | Line 32: | ||
= Treatment = | = Treatment = | ||
*Emergent ophthalmology consult | *Emergent ophthalmology consult | ||
* | *Decrease production of aqueous humor: | ||
#'''timolol 0.5% drop''': blocks beta receptors on ciliary epithelium | #'''timolol 0.5% drop''': blocks beta receptors on ciliary epithelium | ||
#'''apraclonidine 1% drop''': blocks alpha-2 adrenergic receptors | #'''apraclonidine 1% drop''': blocks alpha-2 adrenergic receptors | ||
| Line 41: | Line 41: | ||
##Use one drop every 15 minutes x 2 doses, then every 4 to 6 hours | ##Use one drop every 15 minutes x 2 doses, then every 4 to 6 hours | ||
##Only effective when IOP <40 mm Hg | ##Only effective when IOP <40 mm Hg | ||
*Reduce volume of aqueous humor: | |||
* | |||
#'''mannitol 1–2gm/kg IV''': if no contraindications | #'''mannitol 1–2gm/kg IV''': if no contraindications | ||
*Recheck IOP hourly | |||
=See Also= | =See Also= | ||
Revision as of 23:45, 23 September 2013
Background
Pathophysiology
- Obstructed aqueous outflow tract > aqueous humor builds > increased intraocular pressure (IOP) > optic nerve damage > vision loss
- Increased posterior chamber pressure causes iris to bulge forward (iris bombé) > further obstruction of outflow tract > further increase IOP
- Acute attack is usually precipitated by pupillary dilation
Definition: 3 signs + 2 symptoms
- At least 3 of these signs:
- IOP >21 mm Hg
- Conjunctival injection
- Corneal epithelial edema
- Mid-dilated nonreactive pupil
- Shallow anterior chamber with occlusion
- At least 2 of these symptoms:
- Ocular pain
- Nausea/vomiting
- History of intermittent blurring of vision with halos
Clinical Features
- Abrupt onset of severe eye pain
- Blurred vision
- Frontal or supraorbital headache
- Nausea / vomiting / abdominal pain
Diagnosis
- Fixed, midposition pupil
- Hazy cornea
- Conjunctival injection most prominent at limbus (ciliary flush)
- Rock-hard globe
- IOP >20 mm Hg
Treatment
- Emergent ophthalmology consult
- Decrease production of aqueous humor:
- timolol 0.5% drop: blocks beta receptors on ciliary epithelium
- apraclonidine 1% drop: blocks alpha-2 adrenergic receptors
- acetazolamide 500mg IV or PO: blocks productions of HCO3-, which draws Na+ into the eye; water follows by osmosis to form aqueous humour
- Facilitate outflow of aqueous humor:
- pilocarpine 1%–2% drop: parasympatholytic alkaloid acts on muscarinic receptors found on iris sphincter muscle ==> causes muscle to contract ==> miosis
- In USA - green top
- Use one drop every 15 minutes x 2 doses, then every 4 to 6 hours
- Only effective when IOP <40 mm Hg
- Reduce volume of aqueous humor:
- mannitol 1–2gm/kg IV: if no contraindications
- Recheck IOP hourly
See Also
Source
Tintinalli